Jenny Tröltzsch and Max Grünig presented the project results together with the project partner Hamburgische WeltWirtschaftsInstitut (HWWI) in Hamburg.The final presentation showed that still large knowledge gaps on the costs of climate change and the costs and benefits of adaptation measures exist. The cost-benefit analyses of adaptation measures in Hamburg show a large bandwidths for local case studies. But nevertheless the results suggest that higher benefits than costs exist for several adaptation measures, for example a green roof program. Furthermore, it is important to initiate adaptation activities of private actors, to reduce damages, e.g. from heavy rain events.

The presentation started with a overview on the methodologies of climate change and climate adaptation economics and their usefulness for a priorisation of adaptation measures. Furthermore, the different sectors relevant to climate adaptation were presented, with a focus on two case studies on green roofs (buildings sector) and The extreme rain in June 2011 (Civil Protection Sector).

The general recommendations were of special interest also in the following discussion:

• Early adaptation, if:
  • Costs will not decline over time,
  • Adaptation measures show short-term benefits,
  • Irreversibly damages can be avoided,
  • Adaptation measures show a long implementation time or a time-lage between implementation and effect.
• Adaptation measures should be complementary to each other, affect different sectors and be robust against changes in framework conditions.
• Available methods for cost-benefit or multicriterial analyses are influences by challenges like data availability and expenditure of time.
• Furthermore, user and policymaker should be aware of the used assumptions and the effects on the results. As programmatic a use of decision support tools and guidelines can be recommended. Some of them are already available and current research projects are developing further tools.
• Adaptation measures need a regional assessment, planning and implementation. In the evaluation process local circumstances have to be integrated.
• For public measures the corporations between different authorities and departments are required.